1. Field of the Invention
The present invention relates to a disk brake for vehicles, and, more particularly, to a disk brake for vehicles including a gap adjuster to compensate for a gap between a frictional pad and a disk based upon the wear of the frictional pad.
2. Description of the Related Art
Generally, a disk brake for vehicles is an apparatus that obtains a braking force by partially pressing frictional pads against opposite sides of a disk rotatable along with each wheel of a vehicle. An example of the disk brake includes a disk rotatable along with each wheel of a vehicle, a frictional pad configured to press against one side of the disk to generate a braking force, a wedge member having the frictional pad attached to one side thereof, the wedge member being movable to the rotation direction of the disk by a drive motor to generate a power such that the wedge member advances to the disk, and a guide member to guide the wedge member, such that the wedge member advances to the disk, when the wedge member moves to the rotation direction of the disk, the wedge member being fitted between the disk and the guide member, whereby it is possible to obtain a relatively large braking force using a relatively small power.
The conventional disk brake for vehicles further includes a power transmission unit movable to the rotation direction of the disk by the drive motor to move the wedge member to the rotation direction of the disk.
For the power transmission unit to move to the rotation direction of the disk, as described above, a male screw is formed on a rotary shaft of the drive motor, and the power transmission unit is provided with a shaft installation hole having a female screw is formed on the inner circumference thereof. Consequently, the power transmission unit can advance to or retreat from the rotation direction of the disk according to the rotation direction of the rotary shaft.
The conventional disk brake for vehicles needs a booster to perform speed reduction, displacement reduction, and boosting functions to implement a braking operation using the rotating force of the drive motor. An example of the booster includes a pair of wedge members having inclined surfaces corresponding thereto.
However, the frictional pad gradually wears due to continuous friction between the frictional pad and the disk. As a result, a gap between the frictional pad and the disk gradually increases. If the gap is not compensated for, a braking force and braking responsibility gradually reduce with the progress of the wear of the frictional pad.